Sheet metal can body



Sept. 14, 1937. `w. G. PLUME SHEET METAL GAN BODY Filed April 6. 1957 Patented Sept. 14, 1937.

UNITED STATES PATENT OFFICE p 1 vsnltn'r METAL CAN BODY Walter G. Plumb, indgowooa, N. s., signor-,fo 1 Continental Can Company, Inc., New York, N. Y., a corporation of New York Application April s; 1937, serial No. 135,337

z "claim` (ci. zzo-76) i The invention relates to new and useful improvements in a sheet metal can body. It is a common practice in making can bodies from sheet metal to prepare the blank by shaping the ends thereof to provide hooks which areV interlocked in the forming of'a side seam.' 'I'hese hooks usually extend from one end of .the can body to the other, terminating short of the end where there are lap sections only to facilitate the flanging of the can body. After the hooks have been formed and interlocked and bumped, then solder is applied to the side seam for the solder bonding of the same. I

An object of the present invention is to provide a side seam of the above type wherein the walls of the body within the limits of the side seam are more eiiiciently tied together by the solder bond so as to give strength to the side seam to resi internal pressure.

In the drawing- Figure 1 is a plan view of a body blank embodying' the invention Fig. 2 is a vertical sectional view through the can body showing the formed and solder bonded side seam as viewed from the inside of the can body;

Fig. 3 is a view on an enlarged scale showing a. portion of the side seam and indicating by broken lines, the position and the shaping of the hooks;

Fig. 4 is an enlarged sectional view through a portion of the side seam as it is submitted to the bumping mechanism and prior to the operation of the bumping mechanism thereon;

Fig. 5 is a. view similar to Fig. 4, but showing the bumping iron as having contacted with the can body and the bumping of the side seam completed;

Fig. 6 is a sectional view on the line 6 6 of Figures 2 and 3, and

Fig. '7 is a sectional view on the line 'l-l of Fig.

In carrying out the invention, a sheet of metal is cut so as to provide a body blank which is indicated at l in Fig. 1 of the drawing. The body blank is cut at one end thereof as indicated at 2, so as to provide the usual lap sections 3 and hook sections 4. The hook section 4 is notched at spaced intervals as indicated at 5. These notches are preferably V-shape, that is, the side walls of each notch intersect substantially at an angle of ninety degrees, and the vertex o1' the angle lies within the hook, but close tothe base of the hook, that is, where the metal is folded 66 to form the hook. This hook 4 is the outside hook as shown in Fig. 6, and the base of the hook is indicated at 6. The vertex vofthetriangular notch is also indicated in this Figure at 7. The other end of the `blank is provided with slits I forming the usual lap ysections 9, 9, 'and also forming a hook section III therebetween. Thisf hook section, before the metal is bent to form the hook, is provided with a series of spaced notches II which are similar in shape to the notches 5.'

This hook I0 is the inner hook, .that is, it is car- 10 ried yby the body wall which forms the inside of the side seam. The base of the hook is indicated at I2 in Fig. 5, and the vertex of the notches III is indicated at I3. .I l

After themetal hasbeen notched `and shaped 15 as shown in Fig. 1, then the hook portions are folded back and the body is shaped and the hooks are interlocked. 'I'he notches 5 and II are not only similar'in shape, butfthey are directly opposed to each other, so that when the hooks are 20 interlocked, one notch overlies the other notch, thus forming a substantially rectangular recess I4 as shown in Fig. 3. While these notches are referred to as having the side walls intersecting to. form substantially a right angle, they are 25 preferably curved at the vertex of each notch as shown on an enlarged scale in Fig. 3,.to facilitate the cutting of the notches. The recess I4, however, is substantially rectangular when the side walls of the notches are arranged at the angle 30 stated.`l 'I'hls recess extendsthrough both of the hooks, from the body wall carrying the outer hook to the body wall carrying the inner hook. The recess is wholly within the limits of the side seam where the base of the outer hook is indi- 35 cated by the full line 6 in the drawing, and the base I2 of the inner hook is indicated by broken lines.

'I'he bumping Amechanism is slightly different from that used on an ordinary lock and lap side 40 seam. 'I'he spline I5 is provided with the usual recess I6 to receive they interfolded parts during the bumping operation, and at spaced intervals, the spline is provided with anvil pins' Il. The bumping iron I8 is of the usual` construction and 45 has a smooth face. When the bumping iron is brought into contact with the outer wall of the can body, the interfolded-parts are forced into the recess and against the pins which project into the recess. The corners of the pins are 50 rounded and are dimensioned so that when the metal parts are forced against the pins, the metal in the inner body wall, that is, the body wall carrying the inner hook, will be de-formed and forced into the recess in the outer hook and u part way into the recess in the inner hook, as clearly vshown in Fig. 5 of the drawing. The outer face I9 of the body wall carrying the inner hook, and the inner vface 20 of the body wall carrying 5 the outer hook, are adjacent each other, but slightly spaced. The distance between these faces of the walls is less than the thickness of the metal forming thecan body. The walls are sufficiently close so that the solder'will flow by 10 capillary attraction throughout the entire region of the recess and the side seam. In this recess is formed a. pillar of solder which is fused to the inner and outer walls of the body so that said walls at spaced intervals are vtied together by these pillars of solder. l It is well known that when internal pressure is exerted against the side seam, that the weakest part of the side seam-is midway the length of the side seam. The outward pressure onthe side seam tends to cause the khooks to turn like hinges, rupturing the solder bond by a tension strain thereon. 'I'hese solder pillars at intervals will bind together the inner and outer `walls of the side seam and thus resist this strain which tends to rupture the solder bond and initiate the unhinging action which destroys the side seam.

While thenotches are shown as V-shaped, it is understood that they may be otherwise shaped,

I but it is essential that there shall be a notch in each hook, and that these notches. shall be so disposed as to provide a recess extending from the body wall carrying the inner hook tothe body wall carrying the outer hook, and it is also essential that the metal of at least one of the walls shall be deformed so as to be brought sufiiciently close to the metal of the other Wall within the recess that the solder will flow by capillary attraction throughout the entire limits of the side seam and form these pillars of solder which tie together the inner and outer walls of the side seam.

It will be noted that the bumping iron `has a smooth face, and therefore, the outer wall of the can body will be smooth and free from deformation, while the pins in the spline will deform the inner wall of the can body. The bumping pins may be placed in the horn and the spline smooth,

if it is desired that the inner wall of the can body shall be smooth. In fact, both the spline and the bumping iron may have projecting portions at spaced intervals for de-forming both the inner and outer walls. It is essential, however. that both hooks shall have notches, thus forming a recess e ending all the Way from one body wall 5 to the o her at spaced intervals, and that the body walls shall be broughty suiiiciently close together t insure la solder bonding pillarv joining said walls in the region of the recess.

It is obvious that minor changes in the details 10 of construction and in the shaping of the parts may be made without departing from the spirit of the invention as set forth in the appended claims.

Having thus described the invention, what I Il claim as new and desire to secure by Letters- Patent, ist 1. A metal can body having its edge portions joined ina side seam, said sid seam including interlocking hooks and a solder bondfor uniting 20 as to lie close to but spaced from the other body 30 Wall, whereby the solder bond will form a pillar in each recess joining the body walls.

2. A metal can body having its edge portions joined in a side seam, said side seam including interlocking hooks and a solder bond for uniting said interlocking hooks, each hook being cut away at spaced intervals to form V-shaped notches extending substantially to the base of the hook, said notches in the interlocked hooks being disposed one opposite the other thereby 40 forming a recess extending through both hooks at spaced intervals and within the limits of the side seam, the metal in at least one of the body walls in the region of each recess being deformed into said recess so as to lie close to but 45 spaced from the other body wall, whereby the solder bond will form a pillar in each recess joining the body walls.

WALTER G. PLUMB. o 

